A marine vessel may be equipped with a pod, or azimuth thruster propulsion system. The pod provides both propulsion and steering functions and may be used singly or in pairs. The pod is made up of two units. The first, the upper pod unit, connects to an engine via a driveshaft and contains the gearing and steering functions. The second, the lower pod unit, mounts a propeller and provides an exhaust outlet for the engine. The lower pod unit is external of the hull of the marine vessel and rotates relative to the upper pod unit to provide steering.
The steering system typically includes a steering brake that prevents rotation of the lower pod unless a steering operation is underway. The steering brake will typically be engaged to prevent rotation unless the brake receives a signal to disengage to allow a turning operation. Such a system is disclosed in U.S. Pat. No. 8,408,953 to Bremsjo; et al., issued Apr. 2, 2013, entitled “Arrangement and method for controlling a propeller drive on a boat.” The steering system and steering brake may need periodic servicing. During service, the steering brake may need to be disengaged to allow the lower pod unit to rotate freely. In addition, it may be desirable to service the steering system without the chance of having the lower pod unit perform an uncommanded rotation while a serviceman is in the vicinity.
The system disclosed by Bremsjo et al does not disclose a system or method that allows servicing of the steering and brake system.